Tarzan’s beach club has wifi. They charge 100 pesos for two loungers and an umbrella. For golf cart everyone has their favorites, ours is Ciro’s on Guerrero.
Over on the right hand side there are a series of Top Questions (you may need to access the site with a laptop or Ipad as many cell phones often don’t show full site) and one of them is on golf cart rentals, including addresses and contact info. There’s also one for day trips specifically. The fifth one from top has maps so you can orient yourself.
Can’t help with the cab question as I’ve never taken one to the hotel zone from the ferry.